/*

 * Copyright (c) 1996, 2014, Oracle and/or its affiliates. All rights reserved.

 * DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.

 *

 * This code is free software; you can redistribute it and/or modify it

 * under the terms of the GNU General Public License version 2 only, as

 * published by the Free Software Foundation.  Oracle designates this

 * particular file as subject to the "Classpath" exception as provided

 * by Oracle in the LICENSE file that accompanied this code.

 *

 * This code is distributed in the hope that it will be useful, but WITHOUT

 * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or

 * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU General Public License

 * version 2 for more details (a copy is included in the LICENSE file that

 * accompanied this code).

 *

 * You should have received a copy of the GNU General Public License version

 * 2 along with this work; if not, write to the Free Software Foundation,

 * Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.

 *

 * Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA

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 */

package sun.awt;

import java.awt.peer.FontPeer;

import java.util.Locale;

import java.util.Vector;

import sun.font.SunFontManager;

import sun.java2d.FontSupport;

import java.nio.CharBuffer;

import java.nio.ByteBuffer;

public abstract class PlatformFont implements FontPeer {

    static {

        NativeLibLoader.loadLibraries();

        initIDs();

    }

    protected FontDescriptor[] componentFonts;

    protected char defaultChar;

    protected FontConfiguration fontConfig;

    protected FontDescriptor defaultFont;

    protected String familyName;

    private Object[] fontCache;

    // Maybe this should be a property that is set based

    // on the locale?

    protected static int FONTCACHESIZE = 256;

    protected static int FONTCACHEMASK = PlatformFont.FONTCACHESIZE - 1;

    protected static String osVersion;

    public PlatformFont(String name, int style){

        SunFontManager sfm = SunFontManager.getInstance();

        if (sfm instanceof FontSupport) {

            fontConfig = ((FontSupport)sfm).getFontConfiguration();

        }

        if (fontConfig == null) {

            return;

        }

        // map given font name to a valid logical font family name

        familyName = name.toLowerCase(Locale.ENGLISH);

        if (!FontConfiguration.isLogicalFontFamilyName(familyName)) {

            familyName = fontConfig.getFallbackFamilyName(familyName, "sansserif");

        }

        componentFonts = fontConfig.getFontDescriptors(familyName, style);

        // search default character

        //

        char missingGlyphCharacter = getMissingGlyphCharacter();

        defaultChar = '?';

        if (componentFonts.length > 0)

            defaultFont = componentFonts[0];

        for (int i = 0; i < componentFonts.length; i++){

            if (componentFonts[i].isExcluded(missingGlyphCharacter)) {

                continue;

            }

            if (componentFonts[i].encoder.canEncode(missingGlyphCharacter)) {

                defaultFont = componentFonts[i];

                defaultChar = missingGlyphCharacter;

                break;

            }

        }

    }

    /**

     * Returns the character that should be rendered when a glyph

     * is missing.

     */

    protected abstract char getMissingGlyphCharacter();

    /**

     * make a array of CharsetString with given String.

     */

    public CharsetString[] makeMultiCharsetString(String str){

        return makeMultiCharsetString(str.toCharArray(), 0, str.length(), true);

    }

    /**

     * make a array of CharsetString with given String.

     */

    public CharsetString[] makeMultiCharsetString(String str, boolean allowdefault){

        return makeMultiCharsetString(str.toCharArray(), 0, str.length(), allowdefault);

    }

    /**

     * make a array of CharsetString with given char array.

     * @param str The char array to convert.

     * @param offset offset of first character of interest

     * @param len number of characters to convert

     */

    public CharsetString[] makeMultiCharsetString(char str[], int offset, int len) {

        return makeMultiCharsetString(str, offset, len, true);

    }

    /**

     * make a array of CharsetString with given char array.

     * @param str The char array to convert.

     * @param offset offset of first character of interest

     * @param len number of characters to convert

     * @param allowDefault whether to allow the default char.

     * Setting this to true overloads the meaning of this method to

     * return non-null only if all chars can be converted.

     * @return array of CharsetString or if allowDefault is false and any

     * of the returned chars would have been converted to a default char,

     * then return null.

     * This is used to choose alternative means of displaying the text.

     */

    public CharsetString[] makeMultiCharsetString(char str[], int offset, int len,

                                                  boolean allowDefault) {

        if (len < 1) {

            return new CharsetString[0];

        }

        Vector<CharsetString> mcs = null;

        char[] tmpStr = new char[len];

        char tmpChar = defaultChar;

        boolean encoded = false;

        FontDescriptor currentFont = defaultFont;

        for (int i = 0; i < componentFonts.length; i++) {

            if (componentFonts[i].isExcluded(str[offset])){

                continue;

            }

            /* Need "encoded" variable to distinguish the case when

             * the default char is the same as the encoded char.

             * The defaultChar on Linux is '?' so it is needed there.

             */

            if (componentFonts[i].encoder.canEncode(str[offset])){

                currentFont = componentFonts[i];

                tmpChar = str[offset];

                encoded = true;

                break;

            }

        }

        if (!allowDefault && !encoded) {

            return null;

        } else {

            tmpStr[0] = tmpChar;

        }

        int lastIndex = 0;

        for (int i = 1; i < len; i++){

            char ch = str[offset + i];

            FontDescriptor fd = defaultFont;

            tmpChar = defaultChar;

            encoded = false;

            for (int j = 0; j < componentFonts.length; j++){

                if (componentFonts[j].isExcluded(ch)){

                    continue;

                }

                if (componentFonts[j].encoder.canEncode(ch)){

                    fd = componentFonts[j];

                    tmpChar = ch;

                    encoded = true;

                    break;

                }

            }

            if (!allowDefault && !encoded) {

                return null;

            } else {

                tmpStr[i] = tmpChar;

            }

            if (currentFont != fd){

                if (mcs == null) {

                    mcs = new Vector<>(3);

                }

                mcs.addElement(new CharsetString(tmpStr, lastIndex,

                                                 i-lastIndex, currentFont));

                currentFont = fd;

                fd = defaultFont;

                lastIndex = i;

            }

        }

        CharsetString[] result;

        CharsetString cs = new CharsetString(tmpStr, lastIndex,

                                             len-lastIndex, currentFont);

        if (mcs == null) {

            result = new CharsetString[1];

            result[0] = cs;

        } else {

            mcs.addElement(cs);

            result = mcs.toArray(new CharsetString[mcs.size()]);

        }

        return result;

    }

    /**

     * Is it possible that this font's metrics require the multi-font calls?

     * This might be true, for example, if the font supports kerning.

    **/

    public boolean mightHaveMultiFontMetrics() {

        return fontConfig != null;

    }

    /**

     * Specialized fast path string conversion for AWT.

     */

    public Object[] makeConvertedMultiFontString(String str)

    {

        return makeConvertedMultiFontChars(str.toCharArray(),0,str.length());

    }

    public Object[] makeConvertedMultiFontChars(char[] data,

                                                int start, int len)

    {

        Object[] result = new Object[2];

        Object[] workingCache;

        byte[] convertedData = null;

        int stringIndex = start;

        int convertedDataIndex = 0;

        int resultIndex = 0;

        int cacheIndex;

        FontDescriptor currentFontDescriptor = null;

        FontDescriptor lastFontDescriptor = null;

        char currentDefaultChar;

        PlatformFontCache theChar;

        // Simple bounds check

        int end = start + len;

        if (start < 0 || end > data.length) {

            throw new ArrayIndexOutOfBoundsException();

        }

        if(stringIndex >= end) {

            return null;

        }

        // coversion loop

        while(stringIndex < end)

        {

            currentDefaultChar = data[stringIndex];

            // Note that cache sizes must be a power of two!

            cacheIndex = (currentDefaultChar & PlatformFont.FONTCACHEMASK);

            theChar = (PlatformFontCache)getFontCache()[cacheIndex];

            // Is the unicode char we want cached?

            if(theChar == null || theChar.uniChar != currentDefaultChar)

            {

                /* find a converter that can convert the current character */

                currentFontDescriptor = defaultFont;

                currentDefaultChar = defaultChar;

                char ch = data[stringIndex];

                int componentCount = componentFonts.length;

                for (int j = 0; j < componentCount; j++) {

                    FontDescriptor fontDescriptor = componentFonts[j];

                    fontDescriptor.encoder.reset();

                    //fontDescriptor.encoder.onUnmappleCharacterAction(...);

                    if (fontDescriptor.isExcluded(ch)) {

                        continue;

                    }

                    if (fontDescriptor.encoder.canEncode(ch)) {

                        currentFontDescriptor = fontDescriptor;

                        currentDefaultChar = ch;

                        break;

                    }

                }

                try {

                    char[] input = new char[1];

                    input[0] = currentDefaultChar;

                    theChar = new PlatformFontCache();

                    if (currentFontDescriptor.useUnicode()) {

                        /*

                        currentFontDescriptor.unicodeEncoder.encode(CharBuffer.wrap(input),

                                                                    theChar.bb,

                                                                    true);

                        */

                        if (FontDescriptor.isLE) {

                            theChar.bb.put((byte)(input[0] & 0xff));

                            theChar.bb.put((byte)(input[0] >>8));

                        } else {

                            theChar.bb.put((byte)(input[0] >> 8));

                            theChar.bb.put((byte)(input[0] & 0xff));

                        }

                    }

                    else  {

                        currentFontDescriptor.encoder.encode(CharBuffer.wrap(input),

                                                             theChar.bb,

                                                             true);

                    }

                    theChar.fontDescriptor = currentFontDescriptor;

                    theChar.uniChar = data[stringIndex];

                    getFontCache()[cacheIndex] = theChar;

                } catch(Exception e){

                    // Should never happen!

                    System.err.println(e);

                    e.printStackTrace();

                    return null;

                }

            }

            // Check to see if we've changed fonts.

            if(lastFontDescriptor != theChar.fontDescriptor) {

                if(lastFontDescriptor != null) {

                    result[resultIndex++] = lastFontDescriptor;

                    result[resultIndex++] = convertedData;

                    //  Add the size to the converted data field.

                    if(convertedData != null) {

                        convertedDataIndex -= 4;

                        convertedData[0] = (byte)(convertedDataIndex >> 24);

                        convertedData[1] = (byte)(convertedDataIndex >> 16);

                        convertedData[2] = (byte)(convertedDataIndex >> 8);

                        convertedData[3] = (byte)convertedDataIndex;

                    }

                    if(resultIndex >= result.length) {

                        Object[] newResult = new Object[result.length * 2];

                        System.arraycopy(result, 0, newResult, 0,

                                         result.length);

                        result = newResult;

                    }

                }

                if (theChar.fontDescriptor.useUnicode()) {

                    convertedData = new byte[(end - stringIndex + 1) *

                                        (int)theChar.fontDescriptor.unicodeEncoder.maxBytesPerChar()

                                        + 4];

                }

                else  {

                    convertedData = new byte[(end - stringIndex + 1) *

                                        (int)theChar.fontDescriptor.encoder.maxBytesPerChar()

                                        + 4];

                }

                convertedDataIndex = 4;

                lastFontDescriptor = theChar.fontDescriptor;

            }

            byte[] ba = theChar.bb.array();

            int size = theChar.bb.position();

            if(size == 1) {

                convertedData[convertedDataIndex++] = ba[0];

            }

            else if(size == 2) {

                convertedData[convertedDataIndex++] = ba[0];

                convertedData[convertedDataIndex++] = ba[1];

            } else if(size == 3) {

                convertedData[convertedDataIndex++] = ba[0];

                convertedData[convertedDataIndex++] = ba[1];

                convertedData[convertedDataIndex++] = ba[2];

            } else if(size == 4) {

                convertedData[convertedDataIndex++] = ba[0];

                convertedData[convertedDataIndex++] = ba[1];

                convertedData[convertedDataIndex++] = ba[2];

                convertedData[convertedDataIndex++] = ba[3];

            }

            stringIndex++;

        }

        result[resultIndex++] = lastFontDescriptor;

        result[resultIndex] = convertedData;

        //  Add the size to the converted data field.

        if(convertedData != null) {

            convertedDataIndex -= 4;

            convertedData[0] = (byte)(convertedDataIndex >> 24);

            convertedData[1] = (byte)(convertedDataIndex >> 16);

            convertedData[2] = (byte)(convertedDataIndex >> 8);

            convertedData[3] = (byte)convertedDataIndex;

        }

        return result;

    }

    /*

     * Create fontCache on demand instead of during construction to

     * reduce overall memory consumption.

     *

     * This method is declared final so that its code can be inlined

     * by the compiler.

     */

    protected final Object[] getFontCache() {

        // This method is not MT-safe by design. Since this is just a

        // cache anyways, it's okay if we occasionally allocate the array

        // twice or return an array which will be dereferenced and gced

        // right away.

        if (fontCache == null) {

            fontCache = new Object[PlatformFont.FONTCACHESIZE];

        }

        return fontCache;

    }

    /**

     * Initialize JNI field and method IDs

     */

    private static native void initIDs();

    class PlatformFontCache

    {

        char uniChar;

        FontDescriptor fontDescriptor;

        ByteBuffer bb = ByteBuffer.allocate(4);

    }

}